How to get the optical center of the USD Camera?

[edubya]

I am reconstructing scene points using depth_to_camera reported by Camera and RayCasterCamera and seeing discrepancies. Could be me.

Would appreciate someone's help with a sanity check:

• How do I get the position and orientation of the frame located at the optical center of a Camera and RayCasterCamera object?

[RandomOakForest]

Thanks for posting this. Could you elaborate on how you measure discrepancies? The parameters of the camera may be obtained using Replicator annotators.

[edubya]

I am using the USD camera to get images of the scene and the RayCasterCamera to get depths. I detect corner pixels from USD camera images and the depth at the corresponding pixel from the RayCasterCamera.

I'd prefer to use just a RayCasterCamera for both RGB and depth images, but I was having trouble getting the depth_to_camera from the USD camera to make sense after transforming all points into the same frame. I didn't have the same problem using the RayCasterCamera depth_to_camera.

I'm not sure it is a bug or a dumb mistake I made. Right now I am not seeing any discrepancies with depths from either camera when they are not attached to an articulation (kinematic environment, setting world pose directly).